Cooling of PV Modules by Water, Ethylene-Glycol and Their Combination; Energy and Environmental Evaluation

Nowadays, the environmental crisis, due to the combustion of fossil fuels in thermal power plants has become a global issue. Application of renewable energies is the best strategy to overcome the crisis. The photovoltaic power plants are the most popular alternative for governments. As temperature rises in PV cells, a significant drop in their produced power is observed. Therefore, it is important to lower the cell temperature with an appropriate cooling method. In this paper, three types of cooling fluids; pure water, pure Ethylene-Glycol (EG) and mixture of water/EG with the same ratio, are experimentally investigated. Based on the results, application of pure water in the PVT system, shows better performance than other two fluids. While the conventional PV module has shown the surface temperature of higher than 70 ˚C, the proposed PV modules integrated with pure water, pure EG and water + EG have shown surface temperatures of 32.7 ˚C, 36.6 ˚C and 33.7 ˚C, respectively. The maximum temperature reduction of 37.3 ˚C compared to conventional PV module, increased the output power up to 51%. Accordingly, if conventional PV modules are used for commissioning a nominal 20 kW PV power plant, only 11.7 kW is attained, whereas, water cooled PV modules can improve the output power up to 17.7 kW.